Invulnerability and shadowsphere visual effect conflict

In Heretic, using a Ring of Invincibility and a shadowsphere simultaneously produces a peculiar visual effect on the player's weapon. Although the environment correctly uses the golden invulnerability colormap in the translucency blend, the weapon sprite is blended from its normal colors.

This appears to be because R_DrawFuzzColumn takes a colormap into account when picking an index from the tinttable, but does not apply a colormap to the value retrieved from the tinttable afterwards.